An icon as a reward for hitting mastery level X on a champion.

One thing I've noticed is the growing trend of player icons featuring portraits of various champions, either to accompany a new skin or event, and that's really great, I enjoy being able to rep for some of my favorite champions, and with the Conqueror Karma or Cosmic Reaver Kassadin ones for example. And while maybe, eventually, all champions will get their own icons in due time, right now, many don't, and that's totally understandable. From that stemmed my idea:

When you hit a certain mastery level on any champion, like mastery level 7 (or 8!), what if you'd reward people with an exclusive icon featuring the portrait of the classic skin for said champion (be it a crop of their splash art similar to the icons on the minimap or a completely original piece, personally I'd prefer the later but that wouldn't be my job to decide on that), only obtainable through achieving the mastery? Something cool that could accompany it would be the profile background/banner being set to the champion on the icon you're using rather than a champion you've been playing a lot recently.